In recent years, a new storage technology—a phase-change memory (Phase-Change Memory, PCM) gradually shows a potential of replacing a dynamic random access memory, so that the phase-change memory is highly concerned in the industry. Compared with the dynamic random access memory, the phase-change memory mainly has two major advantages. One is that the phase-change memory is highly integrated and has strong expandability, and the other is that the phase-change memory is energy-saving.
However, a storage unit of the phase-change memory can bear only a certain number of write operations, which is generally around 105 to 108. When the number of write operations exceeds this number, a stuck-at fault (Stuck-at Fault) occurs to the storage unit, so that a new write request cannot change an original written state, and the storage unit is permanently stuck at an originally data written state. A major reason is that after the number of write operations exceeds a certain number, due to frequent expansion and contraction, a heating resistor falls off, so that the storage unit can no longer change a phase state, that is, new data can no longer be written into the storage unit, but a read operation may still be performed on originally-written data.